Fafnir

Tolkien's Gold-Hoarding Fire Dragon

Smaug is the most famous dragon of modern fantasy, appearing in J.R.R. Tolkien's 1937 novel The Hobbit. He is the direct archetype for all subsequent 'fire dragon sleeping atop treasure' imagery. A massive crimson dragon with two legs, a pair of huge bat wings, and devastating fire breath, he conquered the Lonely Mountain (Erebor) two centuries before the story, slaughtering the dwarves of Durin's Folk and stealing all their gold to sleep upon. Bilbo Baggins discovered his vulnerability — a missing scale on his left breast — during their famous riddling encounter, and the human hero Bard the Bowman later struck this exact spot with the Black Arrow, killing him.

The Limbless Ancient Dragon

The wyrm is a primordial limbless and wingless serpentine dragon from Norse mythology and English legends. From the Old English word for serpent or dragon, it preserves a more ancient form than later chromatic dragons or wyverns. Most famously, Norse Jormungand—the world serpent of Midgard—encircles the entire human world by biting its own tail, fated to perish alongside Thor at Ragnarok. English tales of the Lambton Worm and Lyminster Worm tell of village-terrorizing local monsters with massive bodies and deadly venom.